Add trains (#1159)

## Description:

Add a rail network to handle train stations/railroad between structures.

Changes:
- `RailNetwork` is responsible for the train station graph. Use it to
connect new `TrainStations`
- A `RailRoad` connects two `TrainStation`
- No loop possible in the rail network
- Train stations handles its railroads
- Added a layer to draw the railroads under the structures

#### Clusters
- To speed up computations, each `TrainStation` references its own
cluster
- A cluster is a list of `TrainStation` connected with each other,
created by the `RailNetwork` when connecting the station
- Train stations spawn trains randomly depending on its current cluster
size
- A `TrainStation` decides randomly of the train destination by picking
one from the cluster

#### Production building:
- Added a factory which has no gameplay impact currently. _To be
discussed._

#### Train stops:
- When a train reaches a factory, it's filled with a "cargo". The loaded
trains has no impact currently. _To be discussed._
- When a train reaches a city, the player earn 10k gold
- When a train reaches a port, it sends a new tradeship if possible
- If a destination/source is destroyed, the train & railroad are deleted
too


https://github.com/user-attachments/assets/42375c17-9e04-4a42-98d0-708c81ffd609


https://github.com/user-attachments/assets/fbecdb53-a516-4df8-87fb-1f9a62c4efa0



## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

## Please put your Discord username so you can be contacted if a bug or
regression is found:

IngloriousTom

---------

Co-authored-by: Scott Anderson <scottanderson@users.noreply.github.com>

src/core/pathfinding/PathFinding.ts

@@ -2,7 +2,7 @@ import { Game } from "../game/Game";
 import { GameMap, TileRef } from "../game/GameMap";
 import { PseudoRandom } from "../PseudoRandom";
 import { DistanceBasedBezierCurve } from "../utilities/Line";
-import { AStar, PathFindResultType, TileResult } from "./AStar";
+import { AStar, AStarResult, PathFindResultType } from "./AStar";
 import { MiniAStar } from "./MiniAStar";
 
 const parabolaMinHeight = 50;
@@ -89,15 +89,20 @@ export class PathFinder {
   private curr: TileRef | null = null;
   private dst: TileRef | null = null;
   private path: TileRef[] | null = null;
-  private aStar: AStar;
+  private aStar: AStar<TileRef>;
   private computeFinished = true;
 
   private constructor(
     private game: Game,
-    private newAStar: (curr: TileRef, dst: TileRef) => AStar,
+    private newAStar: (curr: TileRef, dst: TileRef) => AStar<TileRef>,
   ) {}
 
-  public static Mini(game: Game, iterations: number, maxTries: number = 20) {
+  public static Mini(
+    game: Game,
+    iterations: number,
+    waterPath: boolean = true,
+    maxTries: number = 20,
+  ) {
     return new PathFinder(game, (curr: TileRef, dst: TileRef) => {
       return new MiniAStar(
         game.map(),
@@ -106,6 +111,7 @@ export class PathFinder {
         dst,
         iterations,
         maxTries,
+        waterPath,
       );
     });
   }
@@ -114,7 +120,7 @@ export class PathFinder {
     curr: TileRef | null,
     dst: TileRef | null,
     dist: number = 1,
-  ): TileResult {
+  ): AStarResult<TileRef> {
     if (curr === null) {
       console.error("curr is null");
       return { type: PathFindResultType.PathNotFound };
@@ -125,7 +131,7 @@ export class PathFinder {
     }
 
     if (this.game.manhattanDist(curr, dst) < dist) {
-      return { type: PathFindResultType.Completed, tile: curr };
+      return { type: PathFindResultType.Completed, node: curr };
     }
 
     if (this.computeFinished) {
@@ -141,7 +147,7 @@ export class PathFinder {
         if (tile === undefined) {
           throw new Error("missing tile");
         }
-        return { type: PathFindResultType.NextTile, tile };
+        return { type: PathFindResultType.NextTile, node: tile };
       }
     }